' PSYSOUND' : A COMPUTER PROGRAM FOR PSYCHOACOUSTICAL ANALYSIS

Abstract

This paper outlines the capabilities of a computer program called ‘PsySound’ (written by the author), which implements a range of psychoacoustical models. The relationship between an acoustic stimulus and the corresponding sensation is no simple matter. While physical measurements are relatively easy to perform, psychoacoustical models are principally available in limited or expensive forms, and in that sense, are unavailable to all but the most specialised researchers. This is a matter of some frustration to researchers, students and educators with limited resources. This paper describes a program called ‘PsySound’, in which several psychoacoustical models are implemented. PsySound is compiled for Macintosh PPC, and is freely available from this author’s web site (http://members.tripod.com/~densil/). This paper primarily refers to the current version of PsySound (version 2.x), which combined what were previously five separate programs into one. PsySound reads 16-bit signed integer sound files, with a sample rate of 44100 Hz, and either 1 or 2 channels. Sound Designer 2, AIFF, and Microsoft Wave formats can satisfy these criteria. It analyses the files in a succession of overlapping 93 ms windows. Results are recorded in four tab-delimited text files: one for level, spectrum and cross-channel time series data; one for loudness and related time series data; one for pitch and related time series data; and one for summary data. The broad structure of the program is shown in Fig. 1.